Flameless, smoke generating signaling material

ABSTRACT

A cool-burning, smoke-generating signaling composition free of oxidized-carbon burning rate accelerant or a magnesium carbonate coolant, wherein the composition comprises a mixture of potassium bromate, KCYAH, an augmenting organic fuel, a solid particulate with selected signaling characteristics, and a polyvinyl alcohol binder.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/537,478, filed Sep. 21, 2011, which is hereby, which is incorporated herein by reference thereto.

TECHNICAL FIELD

Embodiments of the present invention are directed to signaling materials, and more particularly to flameless signaling materials. At least one embodiment of the present disclosure relates to a novel non-traditional signaling material/smoke that significantly reduces the potential for starting a fire during use.

BACKGROUND

Signaling smokes are used for a number of missions ranging from search and rescue to marking/signaling the location of hostile or friendly ground forces to include masking of ground forces from hostile detection. The United States Armed Forces uses signaling material/smokes in the form of multiple colored smoke deployed/delivered by hand-thrown grenades, as well as direct and indirect fire weapon systems. Traditionally, the signaling material is the filler of a projectile that is delivered to the area to be deployed and then ignited with an ignition device, typically a pyrotechnic time fuze in the case of a hand-thrown signaling/masking/marking grenade and the appropriate fuze types; i.e., time/super-quick/impact/multi-function types for direct and in-direct projectiles.

In use, the hand-thrown signaling/masking/marking grenade lands on the ground in the area to be marked, masked, or the signaling location. The time fuze times out and activates the payload ignition system which proceeds to burn inside the grenade body. The payload typically consists of a combustible fuel/oxidizer compound and a signaling material in a mechanical mixture. The heat evolving from the fuel/oxidizer combustion serves to vaporize the signaling material which is then dispersed by the gaseous payload combustion products. These then vent out of the grenade body through provided vent orifices and form a signaling/marking/masking cloud. Direct and indirect fire delivered payloads function in much the same manner as a tactical explosive payload in that the functioning of the fuze initiates an ignition/bursting charge that ignites the payload material as well as bursting the projectile body to release the burning payload material to form signaling/masking/marking cloud. A further derivative of direct and indirect fire delivered payloads would function much the same as submunition-dispensing “cargo” munitions in that a time fuze would function at a pre-determined time, initiating an ejection sequence and ejecting one or more smoke canisters from the delivery projectile. These canisters would then function in the manner described above for the hand-thrown devices.

Although a relatively effective system, numerous disadvantages exist; for example, during the combustion of the payload material, significant heat is evolved which introduces the potential danger of setting nearby ground vegetation and/or structures aflame. Another disadvantage is the toxic nature of the evolved gaseous combustion products that constitute the signaling/masking/marking cloud.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a combustion chamber assembly useable for delivery of the A cool-burning, smoke-generating signaling composition in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

The present disclosure describes a signaling material/smoke that overcomes drawbacks experienced in the prior art and that provides additional benefits. In one embodiment, the signaling material is based upon fire-suppression technology and is configured to significantly reduce the potential for starting a fire during use. Several specific details of the invention are set forth in the following description and the Figures to provide a thorough understanding of certain embodiments of the invention. One skilled in the art, however, will understand that the present invention may have additional embodiments, and that other embodiments of the invention may be practiced without several of the specific features described below.

The non-traditional payload material of one embodiment is a derivative of the cool-burning fire suppressant technology as described in U.S. patent application Ser. No. 13/043,010 (Publication No US 2011/0155943), filed Mar. 8, 2011, published Jun. 30, 2011 by inventors Phillip L. Posson et al; itself claiming priority to U.S. Pat. Nos. 7,407,598 and 7,906,034, all of which are incorporated herein by reference thereto. While the basic cool-burning stoichiochmetry of the disclosed technology is preserved, the signaling material of the current disclosure stems from the vaporization and dispersion of a signaling material by the cool-burning reaction's evolved reaction heat and gaseous combustion by-products augmented by an added organic fuel, typically cornstarch.

The composition of the present disclosure vaporizes a dye for signaling purposes with a much-reduced risk of starting fires in flammable materials like dry grass or papers. It may also be used as a dispersing agent for tear gas, like CS or CN. In this case, it reduces the risk of causing house fires. The basic cool burning fire suppressant composition is blended with the augmenting organic fuel, such as cornstarch, and a tailored solid particulate material possessing the desired signaling characteristics; examples of which are color, obscurants, masking of desired radiation such as ultraviolet, infrared, range finding/targeting/guidance lasers, and the like. The blended materials are processed into a final shape, generally, but not limited to pressing or extrusion, then are loaded into the selected conveyance such as a hand-thrown grenade or direct/indirect fire projectile, employing the appropriate ignition/fuzing system.

In at least one embodiment, the main or only oxidizer is potassium bromate. On reaction, the bromate is reduced to bromide and some of the resulting KBr comes out of the vent(s) with the vaporized agent and other gases. The fuels employed are potassium cyanurate, cornstarch, glycerin plasticizer, and polyvinyl alcohol binder. Potassium cyanurate hydrate is advantageous because its heat of combustion is so low, its nearly-negligible toxicity, its buffering capacity and because of the large amount of nitrogen in its exhaust products.

The potassium cyanurate employed is made in a different manner than the related potassium cyanurate used in the prior art referred to above. The prior art material is made in solution, and the process is all laborious, and the yield of usable product is typically only 80% or less. In the improved method of manufacture in accordance with at least one embodiment of the present disclosure, dry commercial cyanuric acid is placed in a ceramic-lined ball mill with grinding media of alumina or zirconia in the form of cylinders of about ½″ diameter. Then potassium hydroxide pellets (commercial grade, about 85% KOH) are roughly crushed and added to the mill, which is then sealed. The ball mill is then rotated at about 30-120 RPM for ½ hour or more. The mill warms 5-10 degrees F., but there is no other indication of reaction. The entering products are substantially dry so the product will not adhere to the mill walls and grinding media. The product, as monopotassium cyanurate hydrate, is discharged as a fine white powder ready for use. The yield is essentially 100%. The above description is only one embodiment, and other embodiments can use different equipment, operational parameters, temperatures, and/or time periods. This method of manufacture is unexpected in view of the teaching of the prior art.

Unlike the prior art, the present composition burns slowly and controllably at dye content levels of approximately 25-30%, inclusive. Instead of the minor deposit left behind in the burning of the above-referenced prior art flame suppressant mixtures, the mixture of the present disclosure leaves an ash weighing about 30% as much as the beginning charge and considerably larger in volume.

The composition of the present disclosure does not use an oxidized-carbon burning rate accelerant or magnesium carbonate coolant as used in the prior art mixture. The present composition burns at such low temperatures that the display is comparable to hotter military-type mixtures though using only approximately 63-75%, inclusive, as much expensive dye. Less of the dye is pyrolyzed during operation.

Examples of Composition Formulation

At least one embodiment of the composition of the present disclosure consists of, but is not limited to, the following formulation:

Potassium Bromate- 41.89%  KCYAH 19.09%  Corn Starch 5.7% Monarch 1400 0.71%  Red Dye 28.5%  PVAOH 1.8% Glycerin 2.3%

In another embodiment, the composition consists, of but is not limited to, the following formulation:

Potassium Bromate- 41.1% KCYAH 23.1% Corn Starch   6% Monarch 1400 0.75% Red Dye   25% PVAOH  1.9% Glycerin 2.42%

Upon activation, the ignition/fuzing system functions, igniting the intermediary ignition composition/material. As the ignition composition/material reacts, the hot combustion products vent into a specially designed combustion chamber tailored to increase the contact time between the ignition composition/material and the main smoke/signaling material, thus promoting a timely and efficient ignition of the main signaling/smoke composition.

The combustion chamber is in the form of a closed-ended right circular cylinder. A plurality of holes or vents is provided in the closed ends of the combustion chamber arranged such that none of the holes/vents at either end of the combustion chamber are in direct alignment with each other. This arrangement includes a calculated number of holes/vents as well as calculated hole/vent diameters and cross-sectional areas specifically designed to promote turbulent mixing of the hot ignition material/composition combustion products and maximize the contact time between the hot ignition material/composition combustion products and the as yet un-ignited main signaling/smoke material/composition. Furthermore, as the ignition material/composition reaction temperature is required to be greater than the low-temperature main signaling material/composition in order to effect ignition of the main signaling/smoke material/composition, the special tailored design of the combustion chamber vents prevents the premature venting of the hot, burning ignition material composition to the environment where the possibility of setting vegetation and other close proximity combustible materials aflame is present.

As the fire suppressant composition burns, augmented by the added organic cornstarch fuel, the signaling material is vaporized by combustion heat and is dispersed by the low-temperature combustion gasses evolved from the reaction in to a localized cloud. This localized cloud accomplishes the desired signaling/obscurating/masking mission. Meanwhile, as the device is functioning, the device temperature resulting for the fire suppressant material combustion inside is below the ignition point of any environmental material in the immediate region and/or in direct physical contact with the device, thus preventing the ignition and burning of said materials.

The present disclosure describes a flameless signaling material/smoke and related methods in accordance with certain embodiments of the present invention. Several specific details of the invention are set forth in the following description and the Figures to provide a thorough understanding of certain embodiments of the invention. One skilled in the art, however, will understand that the present invention may have additional embodiments, and that other embodiments of the invention may be practiced without several of the specific features described below.

From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the invention. Additionally, aspects of the invention described in the context of particular embodiments or examples may be combined or eliminated in other embodiments. Although advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages. Additionally, not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the invention is not limited except as by the appended claims. 

I/we claim:
 1. A cool-burning, smoke-generating signaling composition comprising potassium bromate and potassium cyanurate hydrate with out using an oxidized-carbon burning rate accelerant and a magnesium carbonate coolant, wherein the composition comprises a combination of potassium bromate, a dry milled KCYAH, corn starch, a dye, polyvinyl alcohol binder, and glycerin.
 2. A cool-burning, smoke-generating signaling composition free of oxidized-carbon burning rate accelerant or a magnesium carbonate coolant, wherein the composition comprises a mixture of potassium bromate, KCYAH, an augmenting organic fuel, a solid particulate with selected signaling characteristics, and a polyvinyl alcohol binder.
 3. The signaling composition of claim 2 wherein the augmenting organic fuel is corn starch.
 4. The signaling composition of claim 2 wherein the solid particulate is a dye.
 5. The signaling composition of claim 2 wherein the solid particulate is a vaporizable dye.
 6. The signaling composition of claim 2 wherein the KCYAH is a dry-milled KCYAH.
 7. The signaling composition of claim 2, further comprising Monarch
 1400. 8. The signaling composition of claim 1, further comprising glycerin.
 9. The signaling composition of claim 2 wherein the amount of potassium bromate is in the range of approximately 40%-42%.
 10. The composition of claim 2 wherein the amount of KCYAH is in the range of approximately 18%-25%.
 11. The composition of claim 2 wherein the amount of augmenting organic fuel is in the range of approximately 5%-7%.
 12. The composition of claim 2 wherein the amount of a solid particulate with selected signaling characteristics is in the range of approximately 25%-30%.
 13. The composition of claim 2 wherein the amount of PVAOH is in the range of approximately 1%-2%.
 14. A flameless, smoke generating signaling material substantially as disclosed herein. 